Amyl nitrite is a chemical compound with the formula C5H11ONO. It's commonly used as a medication to treat angina (chest pain) and as an antidote to cyanide poisoning. It's a vasodilator, meaning it dilates blood vessels, which can help relieve chest pain by increasing blood flow to the heart.

Amyl nitrite reduces left ventricular function, relaxes the smooth muscle of the arteries, lowers arterial blood pressure, and lowers myocardial oxygen consumption. Patients with cyanide poisoning are treated with it, and it is also used to provoke the LVOT gradient during echocardiography in those with hypertrophic cardiomyopathy. Because it produces a quick high and enhances sexual performance, it is overused.

Amyl nitrite Dose in Adults

Amyl nitrite Dose as off-label use in the treatment of Cyanide toxicity:  

• The amyl nitrite comes in small containers called ampuls.
• One ampul, which is about 0.3 milliliters, is opened and crushed.
• The crushed amyl nitrite is put on a gauze pad.
• This gauze pad is then placed in front of the person's mouth.
• If the person can't breathe on their own and has a tube in their throat (called an endotracheal tube), the gauze pad is put near that tube so they can breathe it in.
• The person breathes in the amyl nitrite over about 15 to 30 seconds.
• This process is repeated every minute until they can get proper treatment with other medicines like sodium nitrite.
• Each ampul can last for about 3 minutes, so more ampuls may be needed if the treatment continues.
• It's important to wait at least 30 seconds between each dose to make sure the person is getting enough oxygen.
• Amyl nitrite should only be used as a temporary fix before proper treatment can be given through an IV or until other medicines are ready.

This method is usually used in emergencies, like before the person can get to a hospital or if they can't get an IV right away. It's important to use it carefully and under the guidance of medical professionals.

Amyl nitrite Dose as an off-label application in the treatment of hypertrophic cardiomyopathy with pharmacologic stimulation of the LVOT gradient:

• Amyl nitrite comes in small containers called ampuls.
• One ampul is crushed to release the substance.
• The crushed amyl nitrite is then used for nasal inhalation.
• The person takes 3 to 4 deep breaths of the crushed amyl nitrite over about 10 to 15 seconds.
• This process is used to see if there's a certain type of problem in the heart called a left ventricular outflow tract gradient (LVOT gradient).

It's worth noting that there are other, more natural ways to test for this heart condition, like the Valsalva maneuver or treadmill testing with Doppler echocardiography. These methods might be preferred over using amyl nitrite because they're more like what happens naturally in the body and may be safer.

Amyl nitrite Dose in Children

Amyl nitrite Dose in the treatment of Cyanide toxicity:  

With cyanide poisoning in infants, children, and adolescents, amyl nitrite can be used as a temporary treatment until other medicines can be given.

• The amyl nitrite comes in small containers called ampuls.
• One ampul, which is about 0.3 milliliters, is opened and crushed.
• The crushed amyl nitrite is put on a gauze pad.
• This gauze pad is then placed in front of the person's mouth.
• If the person can't breathe on their own and has a tube in their throat (called an endotracheal tube), the gauze pad is put near that tube so they can breathe it in.
• The person breathes in the amyl nitrite over about 15 to 30 seconds.
• This process is repeated every minute until they can get proper treatment with other medicines like sodium nitrite.
• Each ampul can last for about 3 minutes, so more ampuls may be needed if the treatment continues.
• It's important to wait at least 30 seconds between each dose to make sure the person is getting enough oxygen.
• Amyl nitrite should only be used as a temporary fix before proper treatment can be given through an IV or until other medicines are ready.

This method is usually used in emergencies, like before the person can get to a hospital or if they can't get an IV right away.

Pregnancy Risk Factor C/ X

• During pregnancy, amyl nitrite is not safe to use.
• This is because it can lower blood pressure, which means less blood flow to the baby.
• There haven't been studies on animals to see how it affects pregnancy, but because of these risks, it's not recommended for pregnant people.
• Plus, it could affect the baby's hemoglobin, making it change in a way that's not good for them.

Amyl Nitrite use during breastfeeding:

• It's uncertain whether amyl nitrite passes into breast milk.
• Because of this uncertainty, it's important for nursing mothers to be cautious if they need to use amyl nitrite.
• The manufacturer suggests being careful when using it while breastfeeding.

Amyl nitrite Dose in Renal Disease:

• No recommendations available

Amyl nitrite Dose in Liver Disease:

• No recommendations available

Side Effects of Amyl Nitrite Frequency not defined.

• Central Nervous System:
  • Increased Intracranial Pressure
  • Restlessness
  • Dizziness
  • Headache
• Cardiovascular:
  • Tachycardia
  • Vasodilatation
  • Hypotension
  • Orthostatic Hypotension
  • Cerebral Ischemia
  • Facial Flushing
  • Shock
  • Syncope
• Gastrointestinal:
  • Nausea
  • Faecal Incontinence
  • Vomiting
• Dermatologic:
  • Pallor
  • Skin Irritation
  • Dermatitis
  • Diaphoresis
• Genitourinary:
  • Urinary Incontinence
• Neuromuscular & Skeletal:
  • Weakness
• Ophthalmic:
  • Eye Irritation
  • Increased Intraocular Pressure

• Hematologic & Oncologic:
  • Hemolytic Anemia
  • Methemoglobinemia

Contraindications to Amyl Nitrite Include:

• For individuals with glaucoma, recent head trauma or cerebral hemorrhage, or those who are pregnant, using amyl nitrite for cyanide poisoning might not be safe.
• Additionally, if someone is dealing with both cyanide and carbon monoxide poisoning at the same time, caution is needed when using amyl nitrite.

Warnings and Precautions

Hypotension

• Amyl nitrite can lead to significant drops in blood pressure, causing severe hypotension, even at doses lower than what's usually considered safe.
• It's crucial to closely monitor the patient's blood flow and oxygen levels and ensure they have the right amount of fluids in their body.
• It's best to be cautious when using amyl nitrite in patients where the diagnosis of cyanide poisoning isn't certain, or in those with conditions like smoke inhalation, anemia, or significant blood loss, as they might already have low oxygen levels or heart problems.
• Hydroxocobalamin is suggested as a safer alternative in these cases.

Methemoglobinemia:

• Amyl nitrite can trigger the formation of methemoglobin, which reduces the blood's ability to carry oxygen.
• This can lead to serious issues, even at doses lower than what's normally used for treatment.
• It's essential to keep a close eye on the patient's blood flow and oxygen levels.
• Using amyl nitrite cautiously is advised when the diagnosis of cyanide poisoning isn't certain, or in patients with conditions like smoke inhalation, anemia, or significant blood loss, as they might already have low oxygen levels or heart problems.
• Additionally, patients with a higher risk of developing methemoglobinemia, such as those with congenital methemoglobin reductase deficiency, should be treated cautiously with amyl nitrite.
• It's recommended to consider using hydroxocobalamin instead, especially when there's a chance of using medications that are known to cause methemoglobinemia, like nitroglycerin or phenazopyridine, at the same time.

Aortic stenosis

• In individuals with severe aortic stenosis, extreme caution should be exercised or, in some cases, amyl nitrite should be avoided altogether.
• This caution stems from the possibility that amyl nitrite may decrease blood flow to the heart, potentially leading to ischemia (lack of oxygen supply) in the heart muscle.
• Some medical experts even consider the use of amyl nitrite in such cases to be contraindicated.

Cardiovascular disease

• In patients with cardiovascular disease, including coronary artery disease, and those with low blood pressure, amyl nitrite should be used cautiously.
• There's a risk of experiencing temporary episodes of dizziness, weakness, fainting, or reduced blood flow to the brain due to a sudden drop in blood pressure (postural hypotension).

Increased intracranial pressure

• In patients with increased intracranial pressure, it's important to use amyl nitrite cautiously.
• However, if a patient has recently experienced head trauma or cerebral hemorrhage, the use of amyl nitrite is contraindicated, meaning it should be avoided altogether.
• This caution is because amyl nitrite can further increase pressure within the skull, which can be dangerous, especially in individuals who have recently suffered head injuries or bleeding in the brain.

Amyl nitrite: Drug Interaction

Note: Drug Interaction Categories:

• Risk Factor C: Monitor When Using Combination
• Risk Factor D: Consider Treatment Modification
• Risk Factor X: Avoid Concomitant Use

Monitoring Parameters:

Monitoring during Therapy:

• Blood Pressure and Heart Rate: Keep an eye on blood pressure and heart rate throughout the treatment process.

Cyanide Poisoning:

• Post-Administration Monitoring: Monitor patients for at least 24 to 48 hours after administering amyl nitrite.
• During and After Inhalation: Continuously monitor blood pressure and heart rate during and after amyl nitrite inhalation.
• Other Parameters to Monitor:
  • Hemoglobin and Hematocrit Levels
  • Co-Oximetry (measurement of various forms of hemoglobin)
  • Serum Lactate Levels (indicator of tissue oxygenation)
  • Venous Arterial PO Gradient (difference in oxygen levels between arterial and venous blood)
  • Serum Methemoglobin and Oxyhemoglobin Levels
• Pretreatment Cyanide Levels: Measuring cyanide levels before treatment can be helpful for diagnostic purposes.

How to administer Amyl Nitrite:

Administration Method:

• Route: Nasal inhalation.
• Patient Positioning: The patient should be lying down during administration.

Procedure:

• Prepare the Ampul: Crush the ampul containing amyl nitrite.
• Placement: Place the crushed ampul on a gauze pad.
• Positioning: Position the gauze pad in front of the patient's mouth.
  • If the patient is intubated (has a tube in their throat), position the gauze pad near the endotracheal tube.
• Inhalation: Allow the patient to inhale the amyl nitrite for 15 to 30 seconds.
• Repeat: Repeat the inhalation process every minute until sodium nitrite can be administered.
• Duration: Each ampul lasts for approximately 3 minutes.

Mechanism of action of Amyl Nitrite:

• Amyl nitrite relaxes the muscles in blood vessels, which lowers both venous and arterial blood pressure.
• This helps the heart do its job more easily by reducing the workload on the left ventricle and lowering the amount of oxygen the heart muscle needs.
• In cases of cyanide poisoning, amyl nitrite causes the formation of methemoglobin, which then binds to the cyanide ion.
• This frees up an important enzyme called cytochrome oxidase, allowing normal oxygen use in the body to carry on.

Onset of Action:

• Angina: Begins to take effect within 30 seconds of administration.

Duration:

• Angina: Relief lasts between 3 to 15 minutes.
• Pharmacologic Provocation of LVOT Gradient in HCM: Effects last for approximately 30 seconds.

Absorption:

• Route: When inhaled, amyl nitrite is readily absorbed through the respiratory tract.

Metabolism:

• Process: Metabolized in the liver to form less potent inorganic nitrates.

Half-life Elimination:

• Amyl Nitrite: Less than 1 hour.
• Methemoglobin: Lasts for about 1 hour.

Excretion:

• Route: Eliminated primarily through urine, accounting for approximately 33% of excretion.

International Brands of Amyl Nitrite:

• Amyl Nitrite

Amyl Nitrite Brands in Pakistan:

No brands are available in Pakistan.